Had there been a truly robust system for flight tracking in place that reported 3D position every minute or so from takeoff to touchdown:
1) those with malign motives would have to rule out the possibility of "disappearing" a large commercial aircraft and a few hundred people simply by turning a few cockpit switches or flipping a CB;
2) whether or not this was not the result of a malign act, the CVR and FDR would have been found by now.
Had such a system been in place for AF447, the cause of that crash would have been known with a high degree of certainty at least a year earlier than it was.
ELTs are simply not sufficiently reliable in a crash into water, as AF447 again demonstrated. And it's very hard to find a crash site when it's somewhere in a large body of water without knowing within a a pretty small radius where it was likely to occur. See
Varig 707 1979 disappearance, not to mention the Northwest DC-4 that
vanished over Lake Michigan and, almost 65 years later, still has not been found.
I understand the concern over not being able to shut down an electrical device in case of suspected fire. But there have to be solutions for that. A GPS receiver reporting current 3D position to a satellite every few minutes via SATCOM (perhaps more often in case of altitude or heading changes) does not require a lot of power, nor would one need Li-Ion batteries to power it.
A truly robust system of flight tracking would achieve about 95% of what live streaming of CVR/FDR data would do at far less expense or pilot resistance, and pilots do have a legitimate interest in not having their every remark monitored by the ground.